Expanding root term

This may not quite be an advanced algebraic problem but has been puzzling me for ages now, so though i'd seek help.

So here goes:

I have the equation:

Q = C * ( sqrt ( P1 - P2 ) )

C is constant, P1 and P2 are inputs

Is there a way of rearranging as to seperate P1 and P2 so that the sqrt operation occurs afterwards. The reason for this being that they are pressure inputs into a state space system (simplified - dynamics are there).

This may not quite be an advanced algebraic problem but has been puzzling me for ages now, so though i'd seek help.

So here goes:

I have the equation:

Q = C * ( sqrt ( P1 - P2 ) )

C is constant, P1 and P2 are inputs

Is there a way of rearranging as to seperate P1 and P2 so that the sqrt operation occurs afterwards. The reason for this being that they are pressure inputs into a state space system (simplified - dynamics are there).